1 #ifndef _SCHED_PRIO_H 2 #define _SCHED_PRIO_H 3 4 #define MAX_NICE 19 5 #define MIN_NICE -20 6 #define NICE_WIDTH (MAX_NICE - MIN_NICE + 1) 7 8 /* 9 * Priority of a process goes from 0..MAX_PRIO-1, valid RT 10 * priority is 0..MAX_RT_PRIO-1, and SCHED_NORMAL/SCHED_BATCH 11 * tasks are in the range MAX_RT_PRIO..MAX_PRIO-1. Priority 12 * values are inverted: lower p->prio value means higher priority. 13 * 14 * The MAX_USER_RT_PRIO value allows the actual maximum 15 * RT priority to be separate from the value exported to 16 * user-space. This allows kernel threads to set their 17 * priority to a value higher than any user task. Note: 18 * MAX_RT_PRIO must not be smaller than MAX_USER_RT_PRIO. 19 */ 20 21 #define MAX_USER_RT_PRIO 100 22 #define MAX_RT_PRIO MAX_USER_RT_PRIO 23 24 #define MAX_PRIO (MAX_RT_PRIO + NICE_WIDTH) 25 #define DEFAULT_PRIO (MAX_RT_PRIO + NICE_WIDTH / 2) 26 27 /* 28 * Convert user-nice values [ -20 ... 0 ... 19 ] 29 * to static priority [ MAX_RT_PRIO..MAX_PRIO-1 ], 30 * and back. 31 */ 32 #define NICE_TO_PRIO(nice) ((nice) + DEFAULT_PRIO) 33 #define PRIO_TO_NICE(prio) ((prio) - DEFAULT_PRIO) 34 35 /* 36 * 'User priority' is the nice value converted to something we 37 * can work with better when scaling various scheduler parameters, 38 * it's a [ 0 ... 39 ] range. 39 */ 40 #define USER_PRIO(p) ((p)-MAX_RT_PRIO) 41 #define TASK_USER_PRIO(p) USER_PRIO((p)->static_prio) 42 #define MAX_USER_PRIO (USER_PRIO(MAX_PRIO)) 43 44 /* 45 * Convert nice value [19,-20] to rlimit style value [1,40]. 46 */ nice_to_rlimit(long nice)47static inline long nice_to_rlimit(long nice) 48 { 49 return (MAX_NICE - nice + 1); 50 } 51 52 /* 53 * Convert rlimit style value [1,40] to nice value [-20, 19]. 54 */ rlimit_to_nice(long prio)55static inline long rlimit_to_nice(long prio) 56 { 57 return (MAX_NICE - prio + 1); 58 } 59 60 #endif /* _SCHED_PRIO_H */ 61